Fuel injector troubles
or you can take your injectors off your fuel rails, grab a 12V battery and an air tank. connect the air tank to the injectors (or fuel rail if you took the whole thing off, usually much easier) (regulate the pressure to like 10ppsi or 40psi) and touch the battery terminals to the injector terminals. you should hear them hiss.
if they don't hiss they are not working properly.

